Ecosystem Services and Water Pollution | Grade 3

What makes the edges of a watershed (an area where all water flows to the same place)?

• Slope

• Climate

• Soil type

• Vegetation

Which of the following is NOT a service (helpful thing) provided by the Chesapeake Bay ecosystem (natural area with plants, animals, and water)?

• Water filtration

• Tourism

• Stormwater protection

• Desertification

What happens when too many nutrients get into a lake or pond and cause lots of algae (tiny water plants) to grow?

• A decrease in water salinity

• An algae bloom due to excess nutrients

• An increase in water temperature

• A process of water purification

What can happen when water has too little oxygen (hypoxia) in lakes and oceans?

• Increased fish population

• Formation of dead zones

• Higher oxygen levels

• Enhanced plant growth

Which of these causes too many nutrients to get into lakes and rivers?

• Solar radiation

• Wind erosion

• Sewage treatment plants

• Deforestation

How does sediment pollution (dirt and soil in water) harm aquatic habitats (places where water animals live)?

• Increases water clarity

• Enhances photosynthesis

• Decreases water temperature

• Covers rocky stream bottoms

Which human activity is NOT listed as causing dirt and soil to pollute water?

• Fishing

• Farming

• Urbanization

• Clear-cutting

How do cover crops help stop nutrient runoff (when rain washes plant food away)?

• By anchoring the soil and using excess nitrates

• By increasing soil erosion

• By absorbing carbon dioxide

• By blocking sunlight

How do riparian buffers (plants growing along streams) help keep water clean?

• They increase water acidity

• They act as natural filters for runoff

• They reduce water temperature

• They increase sediment flow

What method helps keep human waste (sewage) from polluting our water?

• Riparian buffers

• Septic tank upgrades

• Cover crops

• Manure lagoons